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An Outbreak of Middle East Respiratory Syndrome due to Coronavirus (MERS-CoV) in Al-Ahssa Region, Saudi Arabia, 2015


During the period between 19 April 2015 (29 Jumada II 1436) and 23 June 2015 (06 Ramadan 1436), a total of 52 laboratory-confirmed cases of Middle East Respiratory Syndrome due to Coronavirus (MERS-CoV) were reported from Al-Ahassa region, eastern Saudi Arabia. The first seven cases occurred in one family, followed by 45 secondary cases in three public hospitals, including eight asymptomatic infections among healthcare workers (HCWs) that occurred in four hospitals in Al-Ahassa. There were two more cases were reported in Al-Dammam and were related to the outbreak (not included in this report). The objectives of the outbreak investigation were to describe the epidemiological characteristic of the MERS-CoV cases in Al-Ahassa region, identify associated potential risk factors, and to identify control measures to be instituted to prevent further occurrence of MERS-CoV among HCWs in Al-Ahassa hospitals.


A complete line-listing of all confirmed cases of MERS-CoV was obtained from the Department of Preventive Medicine, Al-Ahassa General Directorate for Health Affairs, medical records at reporting hospitals, interviews with HCWs and other sources. The outbreak investigation team visited the affected household and interviewed its family members in depth. All actions taken by health authorities to respond to the outbreak were reviewed.


All cases of MERS-CoV during the outbreak were connected. Of all cases, 31 were males (59.6.0%) and 21 were females (40.4%); male-female sex ratio = 1.5. The index case was a 62-year-old male from Al-Ahassa. Three out of the seven family members died as well as 18 of the remaining cases; Case-fatality rate per cent [CFR%] = 40.4%). The epidemic curve suggested that median incubation period is consistently about six days. This outbreak made it very clear that no hospital, doctor or any other HCW is immune against MERS-CoV. The epidemiological findings attribute the occurrence of the cluster of cases to some probable factors related to exposure to large dose of MERS-CoV, denial and other mistaken behaviours of the one of family members, delayed diagnosis, denial among patients, presence of some underlying illnesses, improper risk communication and to inadequate compliance of HCWs and visitors with IPC measures. Other factors that contributed to increased number of cases included laxity and complacency in implementing IPC measures, triaging of patients with acute respiratory infections (ARI) at hospitals, shortage in human resources, laboratory services, case definition and training on standardized case management, and how far should community interventions be.


During the outbreak many ugly rumors were circulating among the public exaggerating the number of cases and giving very unpleasant descriptions of the burial process and the suffering of the affected family. The importance transparency, appropriate risk communication and provision of psychological support to affected families following passing bad news to patients and relatives, societal stigma, limitation in interviewing relatives or patients was discussed.